The hegemony was not secure, nor did it embrace all of the semi-civilized peoples. The Tarascans and other tribes to the west had resisted its power, and shortly before the advent of the Spaniards the Tlascalans to the east had defeated the Aztecs in battle. At the coming of the Europeans the "empire" was losing its hold. The subject peoples were becoming more restless under the burden of tribute; and the ruler, Montezuma II, was a superstitious fatalist. The Spanish conquerors arrived at the opportune moment for success.
Castilla del Oro.--At the same time that the islands other than Española were being occupied, beginnings of settlement were made in Central America. In 1503 Christopher Columbus had attempted to establish a colony on the Veragua coast, but had failed. After several successful trading voyages had been made, however, two colonies were planned for the southern mainland. Ojeda received a grant called Urabá, east of the Gulf of Darién, and Nicuesa obtained a grant called Veragua, lying west of that Gulf. Ojeda founded a colony at San Sebastián (1509), which was shortly afterward moved to Darién, where Vasco Nuñez de Balboa soon became the leading figure and governor _ad interim_ (1511). Nicuesa's colony was founded at Nombre de Diós (1510), but it did not flourish. The Darién region became known as Nueva Andalucía, and in 1513 the whole southern mainland, excepting Veragua, Honduras and Yucatán, to the west and Paria, to the east, was reorganized into one grand jurisdiction called Castilla del Oro, and made independent of Española.
Balboa.--Hearing of gold and a sea toward the south, Balboa led a band of men in 1513 across the Isthmus of Panamá and discovered the Pacific Ocean. The discovery was an important factor in leading to Magellan's great voyage, already recounted, and it set in motion a wave of explorations both up and down the Pacific coast, and led to the conquest of Peru. Balboa had made enemies, and he fell under the suspicion of the new governor of Castilla del Oro, Pedrárias de Ávila, who arrived at Darién in 1514 with a colony of fifteen hundred persons; but a conciliation occurred, and in 1515 Balboa was made Adelantado of the Island of Coíba, in the South Sea. To explore that water he built vessels on the north coast and had them transported across the Isthmus on the backs of Indians. The vessels proved unseaworthy, and while Balboa was building two more at the Isle of Pearls, he was summoned by Pedrárias, charged with treason, and beheaded (1519).